As a technique of causing a transmission apparatus to communicate data to a plurality of reception apparatuses, broadcast communication is known, which transmits the data for the respective reception apparatuses in one packet at once. The broadcast communication is conventionally known as a method capable of efficiently communicating data. In the broadcast communication, however, reception responses readily become redundant. Hence, this method can contrarily be inefficient for communications that require reception responses. Measures for more efficient communication have been proposed in U.S. Patent Application Publication No. 2006/0291410 and Japanese Patent Laid-Open No. 2007-266876.
However, after transmission of a broadcast packet, if a destination node that has received a non-reception response to the broadcast packet resends the packet corresponding to the non-reception response, a communication collision may occur. More specifically, if a receiving-side terminal apparatus which has normally received a broadcast packet receives a non-reception response, the terminal apparatus relays the data to the terminal apparatus that has transmitted the non-reception response. At this time, other receiving-side terminal apparatuses also relay the data to the terminal apparatus that has transmitted the non-reception response.
In this case, collision of relay data disables reliable transmission, and redundant transmission is performed. Especially in a communication method such as a personal area network (to be referred to as a “PAN” hereinafter) where the number of terminal apparatuses is limited, and normal reception occurs at a high probability, each terminal apparatus preferably recognizes the reception states of the remaining terminal apparatuses and sends data only to a terminal apparatus which has not normally completed communication.